Fragrance delivery

ABSTRACT

A substrate such as a fabric may be provided with a fragrance during washing or rinsing process by the addition to the wash water of a free-flowing solid fragrance-providing composition that comprises a fragrance deposited on a particulate carrier along with a water soluble salt of an alkali metal or an alkaline earth metal.

This invention relates to a means of fragrance delivery in washingproducts.

It is desirable to deliver fragrances such as perfumes to substrates bymeans of their incorporation into washing products such as laundrydetergents. However, many washing products contain surfactants, whichform micelles in water, and, as many fragrances are hydrophobic, theytend to migrate to the micelles, rather than deposit on the substrate.

Several methods of overcoming this problem have been tried. One is touse fragrances that are not attracted more to the micelles than to thesubstrate. This is possible, but it restricts greatly the range ofpossible fragrances that can be used.

Various methods have relied on using solid carriers for fragrances.Typical examples of such carriers include inorganic particles, usuallysilica (both precipitated and gel-type). However, the major drawback ofthese methods has been the water insolubility of the carrier.

It has now been found that an inexpensive, convenient method overcomesall these disadvantages and permits the achievement of a fragrance thatis delivered to the substrate. The invention therefore provides a methodof preparation of a free-flowing solid fragrance-providing composition,consisting essentially of the addition of a fragrance to a particulatecarrier material in the presence of a water-soluble salt of an alkali oralkaline earth metal.

The invention additionally provides a free-flowing solidfragrance-providing composition, consisting essentially of a particulatecarrier on which is deposited a fragrance and a water-soluble salt of analkali or alkaline earth metal, the composition comprising at least 60%by weight of water-soluble salt and 20% maximum by weight of particulatecarrier, and the ratio of water-soluble salt to fragrance being from20:1 to 1.5:1.

The compositions of the present invention differ considerably from knowncompositions, which have high proportions of particulate carrier(usually in excess of 40% by weight) and high perfume loadings(typically from 20-50% by weight of the total composition).

In this description, unless otherwise stated, the use of the singularalso includes the plural. For example, “a fragrance” also comprehendsthe case where more than one fragrance is used.

The fragrances for use in this invention may be selected from anysuitable fragrance known to the art. It is a characteristic of thisinvention that an unusually broad range of fragrances may be used.Examples include digeranyl succinate, dineryl succinate, geranyl nerylsuccinate, geranyl phenylacetate, neryl phenylacetate, geranyl laurate,neryl laurate, di(b-citronellyl) maleate, dinonadol maleate,diphenoxyanol maleate, di(3,7-dimethyl-1-octanyl) succinate,di(cyclohexylethyl) maleate, diflralyl succinate, di(phenylethyl)adipate, 7-acetyl-1,2,3,4,5,6,7,8-octahydro-1,1,6,7-tetramethylnaphthalene, ionone methyl, ionone gamma methyl, methyl cedrylone,methyl dihydrojasmonate, methyl1,6,10-trimethyl-2,5,9-cyclododecatrien-1-yl ketone,7-acetyl-1,1,3,4,4,6-hexamethyl tetralin,4-acetyl-6-tert-butyl-1,1-dimethyl indane, para-hydroxy-phenyl-butanone,benzophenone, methyl beta-naphthyl ketone, 6-acetyl-1,1,2,3,3,5hexamethyl indane, 5-acetyl-3-isopropyl-1,1,2,6-tetramethyl indane,1-dodecanal,4-(4-hydroxy-4-methylpentyl)-3-cyclohexene-1-carboxaldehyde,7-hydroxy-3,7-dimethyl ocatanal, 10-undecen-1-al, isohexenyl cyclohexylcarboxaldehyde, formyl tricyclodecane, condensation products ofhydroxycitronellal and methyl anthranilate, condensation products ofhydroxycitronellal and indol, condensation products of phenylacetaldehyde and indol,2-methyl-3-(para-tert-butylphenyl)-propionaldehyde, ethyl vanillin,heliotropin, hexyl cinnamic aldehyde, amyl cinnamic aldehyde,2-methyl-2-(para-iso-propylphenyl)propionaldehyde, coumarin, decalactonegamma, cyclopentadecanolide, 16-hydroxy-9-hexadecenoic acid lactone,1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclo-penta-gamma-2-benzopyrane,beta-naphthol methyl ether, ambroxane,dodecahydro-3a,6,6,9a-tetramethyinaphtho[2,1b]furan, cedrol,5-(2,2,3-trimethylcyclopent-3-enyl)-3-methylpentan-2-ol,2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol,caryophyllene alcohol, tricyclodecenyl propionate, tricyclodecenylacetate, benzyl salicylate, cedryl acetate, para-(tert-butyl) cyclohexylacetate, essential oils, resinoids, and resins from a variety of sourcesincluding but not limited to orange oil, lemon oil, patchouli, Perubalsam, Olibanum resinoid, styrax, labdanum resin, nutmeg, cassia oil,benzoin resin, coriander, lavandin, and lavender, phenyl ethyl alcohol,terpineol, linalool, linalyl acetate, geraniol, nerol,2-(1,1-dimethylethyl)cyclohexanol acetate, benzyl acetate, orangeterpenes, eugenol, diethylphthalate, and combinations thereof.

These fragrances are generally available in liquid form (as solutions inorganic solvent) and this is the form in which they are used in thisinvention.

The carrier material may be any suitable particulate carrier known tothe art to be suitable as a carrier material for fragrances. Preferredare fine, porous silicas. Typical silicas are precipitated silicas, orthey may be fumed silicas. The silicas should have a particle size 2-15μM and a BET surface area of from 140 to 550 M²/g. Preferably thesilicas are capable of adsorbing from 2-3 times their weight infragrance. Suitable silicas of the correct particle size may be providedin that size, or they may be produced from larger particle size silicasby known techniques, such as milling. Typical commercial productsinclude SIPERNAT (trade mark) 22S, 22LS and 50S (ex Degussa). It ispossible to use silica particles of other sizes and hydrophilicity, butthese are less preferred.

Part of the silica can be replaced by other absorbent particulatematerials, such as bentonites and cellulose derivatives (for examplecarboxymethyl cellulose). Up to 50% by weight can be replaced butpreferably the replacement is no higher than 40%, preferably no higherthan 30%.

The water-soluble salts of alkali or alkaline earth metals may be anysuch salts known to the art. Typical examples include sodium andpotassium chlorides and sodium sulphate, sodium chloride beingespecially preferred. Preferably, they should make up at least 60% byweight of the total composition.

Preferably the weight ratio of particulate carrier to water-soluble saltis from 1:2 1 to 1:20, more preferably from 1:5 to 1:20, even morepreferably from 1:10 to 1:20 and most preferably from 1:8 to 1:15. Inaddition, the ratio of water-soluble salt to perfume is preferably from20:1 to 1.5:1, more preferably from 8:1 to 5:1 or from 10:1 to 20:1

A typical composition according to this invention will have 80% salt,10% silica and 10% fragrance. This is in marked contrast to the 50-70%silica and 30-50% fragrance in typical known formulations.

In addition to the essential components mentioned hereinabove, thefragrance-providing compositions according to the invention mayadditionally contain other known ingredients added in art-recognisedquantities to perform their known functions. One such particularlyuseful ingredient is clay, added to give a softening effect.Particularly preferred clays are bentonites. Examples of otherart-recognised ingredients that can be included are antibacterialagents, fluorescing and whitening agents and malodour counteractingagents.

The fragrance-providing compositions according to the invention areprepared by thoroughly mixing the dry ingredients (particulate carrier,salt, other ingredients) and then adding the liquid fragrancecomposition and stirring until a free-flowing dry powder is achieved.Given that the final product is a free-flowing powder, a wide variety ofproportions of ingredients may be used, depending upon the individualnatures of the ingredients, and the skilled person can easily determineappropriate amounts by simple experimentation in every case.

The fragrance-providing compositions of the invention are easily madeand storage stable. The process for their manufacture is simple and doesnot suffer from the high rate of fragrance loss that plagues otherencapsulation techniques. In a wash or rinse liquor, the water-solublesalt dissolves readily, unlike many known compositions, and the releasedfragrance partitions preferably on to the substrate being washed. Theinvention therefore provides a method of applying a fragrance ashereinabove described to a substrate during washing or rinsing,comprising the adding to the wash or rinse water of afragrance-providing composition

The invention is further described with reference to the followingnon-limiting examples.

EXAMPLE 1

Admixtures A-H of the compositions shown in Table 1 below are preparedby blending fumed silica, CMC and sodium chloride and then addingperfume, and mixing until a free-flowing powder is achieved. 0.5 g ofeach is added to one litre of water to give a liquor. A towel is soakedin the liquor for ten minutes and squeezed and dried in open air. TABLE1 A B C D E F G H Sunshine (perfume) 10 20 10 15 10 20 10 15 AEROSIL ®200 5 10 5 5 AEROSIL ® R972 5 10 5 5 Sodium Chloride 85 70 85 75 80 7080 75 BLANOSE ® Refined CMC 5 5 5 5 Total 100 100 100 100 100 100 100100AEROSIL is a fumed silica (trade mark of Degussa).“Blanose” is carboxymethyl cellulose (trade mark of Hercules)

Olfactive evaluations are carried at regular intervals of time by anexpert panel of evaluators.

Performance Rating: 5

---------------4--------3---------2----------→1 Very strongStrong    Fair     Weak      Very Weak

Olfactive Evaluation Scores

Day 1 Day 3 Day 5 Day 7 A 5.0 4.6 4.0 3.1 B 4.8 4.6 4.1 3.0 C 4.6 4.13.6 3.0 D 4.6 4.2 3.5 2.9 E 4.8 4.3 3.2 2.8 F 5.0 4.6 4.3 3.6 G 4.6 3.93.2 2.7 H 4.8 4.1 3.5 3.1

EXAMPLE 2

Example 1 is repeated with compositions J-O as shown in the table below.J K L M N O WaterFall (perfume) 20 30 10 15 10 5 AEROSIL ® 200 5 10 5 54 5 LAUNDROSIL ® DGA 5 10 5 15 6 5 Sodium Sulphate 70 50 80 65 80 85Total 100 100 100 100 100LAUNDROSIL is a detergent-grade bentonite (trade mark of Süd-Chemie AG)

The results are as follows:

Olfactive Evaluation Scores

Day 1 Day 2 Day 5 Day 7 J 5 4.6 4.4 3.8 K 5 4.4 4.0 3.8 L 4.6 4.0 3.42.9 M 4.5 3.9 3.6 3.2 N 4.7 4.0 3.4 3.0 O 4.7 3.8 3.0 2.6

1. A method of preparation of a free-flowing solid fragrance-providingcomposition, comprising the addition of a fragrance to a particulatecarrier material in the presence of a water-soluble salt of an alkali oralkaline earth metal.
 2. A method according to claim 1, in which theweight ratio of particulate carrier to water-soluble salt is from 1:1 to1:20.
 3. A method according to claim 1, in which the weight ratio ofwater-soluble salt to fragrance is from 20:1 to 1.5:1.
 4. A methodaccording to claim 1 in which the particulate carrier is fine, poroussilica, optionally replaced to a maximum of 50% by weight of otherabsorbent particulate materials.
 5. A free-flowing solidfragrance-providing composition, consisting essentially of a particulatecarrier on which is deposited a fragrance and a water-soluble salt of analkali or alkaline earth metal, the composition comprising at least 60%by weight of water-soluble salt and 20% maximum by weight of particulatecarrier, and the ratio of water-soluble salt to fragrance being from20:1 to 1.5:1.
 6. A composition according to claim 1, in which theweight ratio of particulate carrier to water-soluble salt is from 1:2 to1:20, and the weight ratio of water-soluble salt to fragrance is from8:1 to 5:1.
 7. A composition according to claim 6, in which the weightratio of particulate carrier to water-soluble salt is from 1:2 to 1:20,and the weight ratio of water-soluble salt to fragrance is from 10:1 to20:1.
 8. A method of providing a fragrance to a substrate during washingor rinsing, comprising the adding to the wash or rinse water of afree-flowing solid fragrance-providing composition according to claim 5.9. A method according to claim 2, in which the weight ratio ofparticulate carrier to water-soluble salt is from 1:5 to 1:20.
 10. Amethod according to claim 9, in which the weight ratio of particulatecarrier to water-soluble salt is from 1:10 to 1:20.
 11. A methodaccording to claim 2, in which the weight ratio of particulate carrierto water-soluble salt is from 1:8 to 1:15.
 12. A method according toclaim 3, in which the weight ratio of water-soluble salt to fragrance isfrom 8:1 to 5:1.
 13. A method according to claim 12 in which the weightratio of water-soluble salt to fragrance is from 10:1 to 20:1.
 14. Acomposition according to claim 6, in which the weight ratio ofparticulate carrier to water-soluble salt is from 1:5 to 1:20, and theweight ratio of water-soluble salt to fragrance is from 8:1 to 5:1. 15.A composition according to claim 14, in which the weight ratio ofparticulate carrier to water-soluble salt is from 1:10 to 1:20, and theweight ratio of water-soluble salt to fragrance is from 8:1 to 5:1. 16.A composition according to claim 15, in which the weight ratio ofparticulate carrier to water-soluble salt is from 1:8 to 1:15, and theweight ratio of water-soluble salt to fragrance is from 8:1 to 5:1. 17.A composition according to claim 6, in which the weight ratio ofparticulate carrier to water-soluble salt is from 1:2 to 1:20, and theweight ratio of water-soluble salt to fragrance is from 10:1 to 20:1.18. A composition according to claim 7, in which the weight ratio ofparticulate carrier to water-soluble salt is from 1:5 to 1:20 and theweight ratio of water-soluble salt to fragrance is from 10:1 to 20:1.19. A composition according to claim 18, in which the weight ratio ofparticulate carrier to water-soluble salt is from 1:10 to 1:20 and theweight ratio of water-soluble salt to fragrance is from 10:1 to 20:1.20. A method of providing a fragrance to a substrate during washing orrinsing, comprising the adding to the wash or rinse water of afree-flowing solid fragrance-providing composition according to claim 6.